PatternExpert is programmer's learning tool (tutorial and source code examples) aimed at people that want to learn more about software patterns. This is a tutorial for programmers on the 22 most famous patterns, from the 1995 Design Patterns book by the 'gang of four'. Provided with this detailed tutorial and 'how-to' approach are examples for all 22 pattern in the most common languages, C++, C#, and J# which is basically Java.